increment operator

[Nirav Parghi]

Why does this code
public class strprint {
public static void main (String[] args) {
StringBuffer str1 = new StringBuffer(50) ;
for(int i=0; i++<args.length {>
str1 = str1.append(args[i]);
str1 = str1.append(" "); }
System.out.println(str1);
}
}
give me an ArrayOutOfBoundsException ?
strangely, when I substitute with this line
for(int i=0; i<args.length;i++ )>
it works ! (ideally I think this should not happen ?)
I'm confused !!

[faiza haris]

The problem is with line
str1 = str1.append(args[i]); when the argument list is out of bound, then obviously it would give the ArrayOutofBoundException.
I have given the arguments
java hello pal
and after printing these two it gives the Exception.So with minor changes to your code:

public class Strprint {
public static void main (String[] args) {
StringBuffer str1 = new StringBuffer(50) ;
for(int i=0; ;i++)
{str1 = str1.append(args[i]);
System.out.println(args[i]);
str1 = str1.append(" ");
}
//System.out.println(str1);
}
}

[Anonymous]

It is more readeable by using the [ c o d e ] and [ / c o d e ] (remove spaces) UBB tags respectively before and after your code samples.
You must also put spaces around the < character!
Like this:

public class Strprint {
    public static void main (String[] args)
    {
        StringBuffer str1 = new StringBuffer(50) ;
        for (int i=0; i < args.length; i++)
        {
            str1 = str1.append(args[i]);
            System.out.println(args[i]);
            str1 = str1.append(" ");
        }
        System.out.println(str1);
    }
}

PS: To learn more about UBB, click HERE.
Cheers,
Beno�t
[This message has been edited by Beno�t d'Oncieu (edited November 01, 2000).]

[rajesh dalvi]

It gives ArrayIndexOutOfBoundsException for the last element.
This is because first condition is checked and then immdiately it increaments i.
so for last element value of i is actualy args.length.
here is some alternate working code:-

public class strprint {
public static void main (String[] args) {
StringBuffer str1 = new StringBuffer(50) ;
for(int i=0; i < args.length; ) {
str1 = str1.append(args[i++]);
str1 = str1.append(" "); }
System.out.println(str1);
}
}
value of i should be incremented after use in args[i]

[This message has been edited by rajesh dalvi (edited November 01, 2000).]